This invention relates to deicing and anti-icing compositions for use in preventing or reducing ice and snow accumulation on surfaces, such as roads, driveways, walks, airport runways, and vegetation using biodegradable materials.
Deicing compositions are widely used during inclement weather for deicing and preventing snow and ice formation on roads, sidewalks, airport runways, and many other surfaces. Desired properties and effects of deicing preparations include cost-effectiveness, ease of application to roads or other surfaces, prevention of ice formation, reduction of the bonding of snow to the surface of the road, non-corrosive, biodegradeable, safe for the environment, ability to penetrate ice and snow on roads, rapid dissolution after application of the solid mixture, and low or no conductivity on surfaces.
Chlorides, such as sodium, calcium, and magnesium chloride, are effective and inexpensive deicing compounds. Calcium and magnesium chlorides offer the additional benefit of being exothermic upon dissolution, and therefore effective in melting ice even at low temperatures. The use of chlorides as deicers has several drawbacks, however. For instance, the massive use of chloride salts for roadway deicing has been questioned because of residual effects on the environment, such as the pollution of aquatic habitats, ground water, and roadside vegetation. Chloride salt use has also been associated with corrosion and/or deterioration of concrete and metals used in infrastructures. In addition, calcium and magnesium chlorides can be hazardous to human health if inhaled or digested, and leave a slippery residue that is difficult to clean. Both calcium and magnesium chloride salts are also hygroscopic, which can cause them to clump and liquefy during storage.
Alternative anti-icing and deicing materials have been the continuing subjects of scientific and industrial interest. Calcium magnesium acetate (CMA) and methanol are effective and non-corrosive deicing chemicals. CMA competes well with sodium chloride for this purpose, particularly with respect to biodegradability and environmental safety. The use of CMA as a deicer is limited, however, due to its relatively high cost of production. Similarly, potassium acetate has proven especially effective in deicing applications in airports, but too expensive for conventional applications.
Some amelioration of the adverse effects of chlorides has been achieved through the addition of carbohydrates to deicing compositions. Native or modified polysaccharides derived from either starch or cellulose have proven useful in deicing highways when mixed with chloride salts. Low molecular weight (i.e.  less than 1000) sugars applied in concentrated solutions have proven useful in freezing point depression. The presence of glucose or fructose in deicing and/or anti-icing solutions synergistically inhibits or reduces the corrosive effects of chloride salts. Methyl glucoside and other methyl oligo-glycosides combined with chloride salts are also effective in increasing the rate of ice melting and helping other deicing chemicals work at lower temperatures.
The present inventors have now surprisingly found that chloride salts that are conventionally used in deicing compositions may be replaced with the unfractionated product from the alkaline degradation of reducing sugars. These novel deicing compositions eliminate the deleterious effects associated with conventional chloride-containing deicing compositions.
It is therefore a primary objective of the present invention to provide a novel composition for deicing and preventing the formation of ice and snow on surfaces.
It is a further objective of the present invention to provide a composition for deicing and preventing formation of ice and snow on surfaces that does not contain chlorides.
It is still a further objective of the present invention to provide a composition for deicing and preventing formation of ice and snow on surfaces that may be isolated from agribusiness waste streams.
It is yet a further objective of the present invention to provide a composition for deicing and preventing formation of ice and snow on surfaces that is biodegradeable.
It is still a further objective of the present invention to provide a composition for deicing and preventing formation of ice and snow on surfaces that is environmentally safe.
It is another objective of the present invention to provide a composition for deicing and preventing formation of ice and snow on surfaces that is effective in depressing the freezing point of water.
It is a further objective of the present invention to provide a composition for deicing and preventing formation of ice and snow on surfaces that is economical to manufacture and easy to store.
These and other objectives will become clear from the foregoing detailed description.
The present invention is directed to a composition for deicing and preventing the formation of ice and snow on surfaces, such as roadways, walks, driveways, and airport runways. The deicing composition consists of the unfractionated product from alkaline degradation of reducing sugars. The preferred source of reducing sugars for this purpose is waste streams from agribusinesses and, most preferably, corn steep water.
Reducing sugars degraded in accordance with this invention are effective in increasing the ionic strength and the depression of the freezing point of water without the inclusion of corrosive chloride salts. The resulting compositions are environmentally safe and biodegradeable, and further make use of readily available, inexpensive starting materials.